The Re-Fuel Action Pack also comes in 12-hour and 24-hour sizes. Beware: the action pack is only waterproof when paired with Hero 3+ and Hero 4 housings (the housing for Hero 3 is slightly too large for a good seal). The pack attaches to the camera by replacing the standard backdoor with the battery pack. For more info or to buy, see http://www.re-fuel.com.

It's easy to forget just how bulletproof a GoPro is. Just 15 years ago, the only folks with a video camera made to handle rain, snow, rocks and the rest were professional videographers with a budget in the tens of thousands of dollars (or more) for equipment alone. And, even then, those all-terrain cameras were big and bulky and technically complex.

In other words, GoPro changed the game when it released the original digital Hero in 2006. The California-based manufacturer basically invented the action sports camera industry by giving the everyman access to top-of-the-line, full-HD equipment with slow-mo capabilities. Never mind that the original interface was clunky and came with no in-field review feature — the Hero's fisheye lens is now the de facto perspective for almost everything extreme and bada**. That's industry cache you just can't buy.

The lens quality and interface has improved with every new generation, but, for one reason or another, GoPro has hardly touched a seemingly small factor: battery life. Like its great-great-grandfather, the Hero 4 gets about an hour of juice in average conditions before needing a recharge.

It seems like a small complaint for a 1080p camera made to take a beating — our office Hero 3 has captured at least 1,000 hours of bike footage in rain, snow and shine, and it's still kicking like the day we took it out of the box — but battery life is a major limitation in the field, especially with no factory option for a removable, rechargeable battery. (Wouldn't it be nice to have three or four small batteries like an SLR camera?)

I can't remember how many times I've cut a ride short (or missed an incredibly scenic section) because the GoPro was down to a blinking battery bar after only an hour, and, in all honesty, I don't want to know. In the frigid cold of winter, it's even worse: anywhere from 20 to 40 minutes, and that's with it shoved in a chest pocket between every 30-second clip.

Enter the Re-Fuel Action Pack series, a suite of three battery packs made to boost your GoPro's life in the field. The original (and smallest) of the suite is the six-hour model. It weighs a measly 2.68 ounces and is barely bigger than a Hero 4. Like the best GoPro accessories, it's easy to use: detach the back door from the waterproof GoPro case, clip the battery pack in place and ratchet the clip as usual. The entire GoPro system has always reminded me of Legos — simple, elegant, almost endlessly interchangeable — and the Re-Fuel batteries are no different. But do they work in practice?

Recommended Stories For You

Field test

In short, yes. The six-hour model lasted anywhere from six to seven hours before reverting to the GoPro's internal battery, and that meant peace of mind on the trail. The pack performed just fine when filming continuously — no need to keep a vigilant eye on the battery bar — and fit like a glove with Hero 4 components. Again, it's like Legos for an adult, and it worked wonderfully — most of the time.

But beware: The Re-Fuel packs are only compatible with the latest GoPros. The waterproof case on our office model, the Hero 3, was slightly too big for a good seal. I couldn't even latch it without seeing the clasp bend. That's not exactly a negative — just something to know before you buy.

Which brings me to a bigger issue: versatility. GoPros are popular because they can go virtually anywhere. Add a battery pack, though, and no matter how sleek, it still doubles the camera profile. This becomes painfully noticeable with different mounts, like the chest mount we use for bike-guide videos. With the Re-Fuel attached, the camera was too bulky to point straight ahead — it either pointed too far down or too high up.

That said, the battery pack worked just fine with a helmet mount and selfie stick. It also worked fine with a handlebar mount, but those have always been jittery on steep, rocky terrain, and adding a few extra ounces doesn't help.

Verdict

The Re-Fuel Power Pack is a must for anyone who films seriously with a GoPro. It gives you at least six hours of trustworthy battery life — the kind the camera itself just can't provide — and, when paired with the latest technology in the Hero 4, it's like a whole new camera. Not bad for $50.

The Re-Fuel Action Pack also comes in 12-hour and 24-hour sizes. Beware: the action pack is only waterproof when paired with Hero 3+ and Hero 4 housings (the housing for Hero 3 is slightly too large for a good seal). The pack attaches to the camera by replacing the standard backdoor with the battery pack. For more info or to buy, see http://www.re-fuel.com.